Stating someone has negative features and his claim is invalid is an example of which fallacy?

A "fallacy" is a mistake, and a "logical" fallacy is a mistake in reasoning. There are, of course, other types of mistake than mistakes in reasoning. For instance, factual mistakes are sometimes referred to as "fallacies". [ [ However, the Fallacy Files is specifically concerned, not with factual errors, but with logical ones. ] ]